The present invention is directed toward an apparatus and method for securing one or more expansion boards of a computer.
The functionality of computers is enhanced by including the ability to accept peripheral systems into the computer. One of the primary means of providing added functionality is to include slots into which additional xe2x80x9cexpansion boardsxe2x80x9d can simply be inserted. It is a standard practice in the art of computer design to provide for the mounting of expansion boards perpendicular to a main computer board or xe2x80x9cmotherboard.xe2x80x9d Graphics cards, sound cards, video cards, and modem cards are typical expansion boards.
Because expansion boards are not soldered into place on the motherboard, it is possible that the boards will become dislodged, lose electrical connectivity, and cease to function properly. A number of designs have been proposed to adequately secure expansion boards to the motherboard. The standard configuration uses one screw per expansion board to secure one side of a mounting plate to the chassis of a computer. The mounting plate is secured to the expansion board. The other end of the mounting plate is inserted into a slot in the chassis. The expansion board is thus fastened relative to one wall of the computer chassis. This design assumes that the chassis is adequately stiff to prevent the motherboard, which is attached to one wall of the chassis, and the expansion board, which is attached to a second wall of the chassis, from moving relative to one another.
It has become evident to those skilled in the art that an expansion board may still become dislodged from the motherboard even though fastened to one side of the computer chassis. Expansion boards are particularly susceptible to becoming dislodged when the board is located away from a wall of the chassis. When a board is located away from the wall of the chassis, that is, near the middle of the computer box, there is a lack of lateral stiffness in the wall of the chassis to which the motherboard is connected. Therefore, flexing of the chassis wall to which the motherboard is connected causes relative movement between the motherboard and the expansion board. Consequently, shaking of the computer or flexing of the chassis during shipping or handling can result in disconnection of expansion boards from the motherboard. Disconnection is also possible with computers used in non-stationary applications.
It can be a major inconvenience to a computer user when an expansion board is dislodged. For a user unfamiliar with the symptoms of the problem, it appears that the computer is materially defective. Even after the problem is identified, it is inconvenient and time consuming to partially disassemble the computer and re-seat the expansion boards. The superior alternative is to prevent the expansion boards from ever becoming dislodged from the motherboard.
The problem of expansion type boards becoming unseated has been addressed by the prior art. For example, in U.S. Pat. No. 5,603,628 a pair of straps is used to hold a circuit board in a connector slot. A problem with the ""628 patent design is that the straps pass over and through the components of the board. Therefore, there is a possibility of damage to the board and the components of a board during installation or adjustment of the straps. Additionally, the ""628 patent requires that connection anchors be added to the connector slot. The anchors not only broaden the connector slot and consume motherboard area, but also require special manufacturing.
The specific problem of expansion board retention in a personal computer was addressed in U.S. Pat. No. 5,715,146. However, the ""146 patent requires separate size adapter members to adequately secure expansion boards of differing heights. For each height of expansion board, a different size adapter must be added to the post member that supports the board. With different size adapters, production costs are increased and the possibility of manufacturing errors increases.
The prior art fails to provide an economical expansion board retention system that does not interfere with the components of the expansion board or consume motherboard area. Under the prior art, numerous adapters of varying sizes may be required to compensate for the fact that expansion board cards are not uniform in height. Consequently, there is a need for an apparatus and method that adequately secures expansion boards to a motherboard without interfering with the components of the expansion board or the components of the motherboard. An improved apparatus would reduce the number of parts required to effect stabilization of the expansion boards.
One embodiment of the invention is a retention block for securing an expansion board. The embodiment has a base with a fastener groove for accepting a fastener and a nose opposite to the base for securing the expansion board.
Another embodiment of the invention is a computer system comprising: a chassis; a support rail coupled to the chassis; a fastener interfacing with the support rail; a retention block coupled to the fastener including a base with a fastener groove for accepting the fastener and a nose at the opposite end of the retention block from the base; and an expansion board interfacing with the nose of the retention block, the expansion board being secured relative to the chassis to prevent electrical disconnection of the expansion board.
Still another embodiment of the invention is a method of manufacturing a computer system comprising the acts of: inserting an expansion board into a slot on a computer motherboard; adjusting the position of the retention block so that the nose of the retention block interfaces with the expansion board; and attaching the base of a retention block to a support member with a fastener.